Base for disposable selectable torque limiting device

ABSTRACT

A unitary base for a torque limiting device is disclosed. The base accepting a plurality of swappable torque limiting fixtures (STLF), whereby a single unitary disposable plastic base may be utilized to form a variety of different specific torque limiting devices and a method to construct and configure such a device.

RELATED APPLICATIONS

This application claims the full Paris Convention priority to, andbenefit of, U.S. provisional application No. 61/694,980, filed on Aug.30, 2012, the contents of which is incorporated by this reference, as iffully set forth herein, in its entirety.

BACKGROUND

1. Field

This disclosure relates to a medical use driver tool and, in particular,to a torque-limiting driver base with selectable fixed torque modules,which driver disengages at a predefined torque limit.

2. General Background

Torque-limiting drivers are widely used throughout the medical industry.These torque-limiting drivers have a factory pre-set torque to ensurethe accuracy and toughness required to meet a demanding surgicalenvironment.

The medical industry has made use of both reusable and disposabletorque-limiting drivers. In a surgical context, there is little room forerror, and these drivers must impart a precise amount of torque.

Reusable drivers require constant recalibration to ensure that thedriver is imparting the precise amount of torque. Recalibration is acumbersome task, but must be done routinely.

Disposable drivers are an easy to use and reliable alternative to thereusable drivers. Typically, each implant, for example, is packaged witha disposable driver designed to the implant's specifications. Once thedriver has been used, it can be discarded. Thus, a surgeon can havecomplete confidence that the disposable driver, packaged with animplant, will impart the precise amount of torque.

DESCRIPTION

Torque is a measure of how much force acting on an object causes thatobject to rotate. In the case of a driver and a fastener, thismeasurement can be calculated mathematically in terms of the crossproduct of specific vectors:T=r×F

Where r is the vector representing the distance and direction from anaxis of a fastener to a point where the force is applied and F is theforce vector acting on the driver.

Torque has dimensions of force times distance and the SI unit of torqueis the Newton meter (N m). The joule, which is the SI unit for energy orwork, is also defined as an N m, but this unit is not used for torque.Since energy can be thought of as the result of force times distance,energy is always a scalar whereas torque is force cross-distance and sois a vector-valued quantity. Other non-SI units of torque includepound-force-feet, foot-pounds-force, ounce-force-inches,meter-kilograms-force, inch-ounces or inch pounds.

A low cost, limited use, torque limiting driver will provide a series oftorque limited tightening.

In some exemplary implementations aspects of a torque limiting devicehaving a hollow body with and open proximal end and open distal endforming a handle; an internal wall bisecting said hollow body into afirst and a second section; a channel formed through said internal wallfluidly connecting said first and said second sections; a nose supportedon a circular base which fits movably into said hollow body; a frontside of said nose with a tool extending therefrom; a backside with saidnose having gears, an extended neck and a pin mounting guide and abearing surface; a clutch having gears on its top, a pass throughchannel therein, an annular wall surrounding the gear, a bearing surfacesurrounding the gear, and a drive catch formed in the annular wall; aswappable torque limiting fixture (STLF) having an elongated body with apin at one end and a flange with bearing at the other end; a drivespline extending from the internal wall of the hollow body and alignedwith the drive catch; and, wherein the torque limiting device is formedby affixing the swappable torque limiting fixture and coil spring to thepin mounting guide via the pass through channel are disclosed. In someinstances a circular cap fitted into the distal end of the body.

In some exemplary implementations, aspects of a torque limiting devicehaving a hollow body with and open proximal end and open distal endforming a handle; an internal wall bisecting said hollow body into afirst and a second section; a channel formed through said internal wallfluidly connecting said first and said second sections; a nose supportedon a circular base which fits movably into said hollow body; a frontside of said nose with a tool extending therefrom; a backside with saidnose having gears, an extended neck and a pin mounting guide and abearing surface with a visual identifier on the back surface ; a clutchhaving gears on its top, a pass through channel therein, an annular wallsurrounding the gear, a bearing surface surrounding the gear, and adrive catch formed in the annular wall; a swappable torque limitingfixture (STLF) having an elongated body with a pin at one end and aflange with bearing at the other end; a drive spline extending from theinternal wall of the hollow body and aligned with the drive catch; and,wherein the torque limiting device is formed by affixing the swappabletorque limiting fixture and coil spring to the pin mounting guide viathe pass through channel are disclosed.

In some exemplary implementations, there is disclosed aspects of atorque limiting device having a hollow body with an open proximal endand open distal end forming a handle; an internal wall bisecting saidhollow body into a first and a second section; a channel formed throughsaid internal wall fluidly connecting said first and said secondsections; a nose supported on a circular base which fits movably intosaid hollow body; a front side of said nose with a tool extendingtherefrom; a backside with said nose having gears, an extended neck anda pin mounting guide and a bearing surface with a visual identifier onthe back surface; a clutch having gears on its top, a pass throughchannel therein, an annular wall surrounding the gear, a bearing surfacesurrounding the gear, and a drive catch formed in the annular wall; aswappable torque limiting fixture (STLF) having an elongated body with apin at one end and a flange with bearing at the other end; a drivespline extending from the internal wall of the hollow body and alignedwith the drive catch; and, wherein the torque limiting device is formedby affixing the swappable torque limiting fixture and coil spring to thepin mounting guide via the pass through channel and a circular cap isfitted into the distal end of the body with a window through the back ofthe cap are disclosed.

In some exemplary implementations, there are disclosed aspects of amethod of selecting a specific torque limiting stroke setting for atorque limiting device, the method comprising: having a unitary base.The unitary base may include a hollow handle with a bisecting wall influid communication with a front and a back section of the handle formedthereby; having a drive spline extended on the interior of the backsection wall for imparting force at a predetermined torque limit to aclutch; placing a movable unitary nose with a tool on its top and amounting guide and gear its backside into the front section of the base;placing a unitary clutch with a pass through channel and a gear thatmates with the nose gear inside the back section with the gear againstthe nose gear; selecting one of two or more swappable torque limitingfixtures (STLF), each of which has a predetermined torque rating, amounting pin and a bearing flange; placing a coil spring around thetorque limiting fixture and against the bearing flange; and, passing thepin through the pass through channel and affixing it into the mountingguide whereby the device has a fixed torque limit which is differentthan the torque limit would have been had another STLF been selected.

In some exemplary implementations, there is disclosed aspects of amethod of selecting a specific torque limiting stroke setting for atorque limiting device, the method comprising: having a unitary hollowhandle base with a bisecting wall in fluid communication with a frontand a back section formed thereby; having a drive spline extended on theinterior of the back section wall for imparting force at a predeterminedtorque limit to a clutch; placing a movable unitary nose with a tool onits top and a mounting guide and gear its backside into the frontsection of the base; placing a unitary clutch with a pass throughchannel and a gear that mates with the nose gear inside the back sectionwith the gear against the nose gear; selecting one of two or moreswappable torque limiting fixtures (STLF), each of which has apredetermined torque rating, a mounting pin and a bearing flange, withan identifier on the backside of the bearing flange; placing a coilspring around the torque limiting fixture and against the bearingflange; a end cap with a window that aligns with the identifier and,passing the pin through the pass through channel and affixing it intothe mounting guide whereby the device has a fixed torque limit which isdifferent than the torque limit would have been had another STLF beenselected.

In some exemplary implementations, there is disclosed aspects of a kitfor forming a torque limiting device comprising: a selection of aplurality of STLFs; a coil spring; a partially assembled torque limitingdevice with a movable nose on one side of a bisecting wall in a hollowbody and connected movably to a clutch, via gears, on the other side ofthe bisecting wall; a mounting guide whereby the pin at one end of aSTLF may be mounted into a guide on the backside of the nose; and, adrive spline which aligns with a drive catch on the annular wall of theclutch.

In some exemplary implementations, there is disclosed aspects of a kitfor forming a torque limiting device comprising: a partially assembledtorque limiting device comprising; a hollow body with and open proximalend and open distal end forming a handle; an internal wall bisectingsaid hollow body into a first and a second section; a channel formedthrough said internal wall fluidly connecting said first and said secondsections; a nose supported on a circular base which fits movably intosaid hollow body; a front side of said nose with a tool extendingtherefrom; a backside with said nose having gears, an extended neck anda pin mounting guide and a bearing surface; a clutch having gears on itstop, a pass through channel therein, an annular wall surrounding thegear, a bearing surface surrounding the gear, and a drive catch formedin the annular wall; a selection of swappable torque limiting fixture(STLF) each having an elongated body with a pin at one end, a flangewith bearing at the other end and an identifier on the STLF providing avisual cue corresponding to the torque properties of the device if ituses that particular STLF; a drive spline extending from the internalwall of the hollow body and aligned with the drive catch; and, whereinthe torque limiting device is formed by affixing the selected swappabletorque limiting fixture and coil spring to the pin mounting guide viathe pass through channel.

DRAWINGS

The above-mentioned features of the present disclosure will become moreapparent with reference to the following description taken inconjunction with the accompanying drawings wherein like referencenumerals denote like elements and in which:

FIGS. 1A and 1B show an external overview of exemplary implementationsof a torque limiting device;

FIG. 2 shows a front to rear assembly view of some aspects of anexemplary implementation of a torque limiting device;

FIG. 3 shows a rear to front assembly view of some aspects of anexemplary implementation of a torque limiting device;

FIG. 4 shows an assembled torque limiting device with a partiallycut-away handle.

FIG. 5 shows a cut-away view of an assembled torque limiting device.

FIG. 6 shows a drive mechanism in a torque limiting device.

FIGS. 7A and 7B show the modular torque setting button.

FIG. 8 shows a cut away component view of the modular button and nosespring assembly.

FIGS. 9A-9E show pin and nose configurations.

While the specification concludes with claims defining the features ofthe present disclosure that are regarded as novel, it is believed thatthe present disclosure's teachings will be better understood from aconsideration of the following description in conjunction with theappendices, figures, in which like reference numerals are carriedforward. All descriptions and callouts in the Figures are herebyincorporated by this reference as if fully set forth herein.

FURTHER DESCRIPTION

Referring to FIGS. 1A-1B there is disclosed a torque limiting driver 10having a plastic molded body 100 which also may function as a handle anda tool 200 with a tip 210 on one end, said tool being fitted into amovable nose 300.

In FIGS. 2-6, there are shown various aspects, use and assembly views ofexemplary implementations of torque-limiting drivers. Thetorque-limiting driver's molded body 100 is generally hollow with anopen proximal end 115, an open distal end 120, and an internal circularwall 130 bisecting the handle into a front section 135 and a backsection 145. There is fluid communication between the front and backsection via centered channel 150.

A circular cap 400 with a backside 402, a front side 404, and an annularwall 410 which extends from said front side of a size and shape to forma latch with said open distal end 120. Optionally a window 420 may beformed in our through said circular cap 400 to allow a view to internalstructures.

The tool 200 with tip 210 at its distal end has a fixed mount 220 at itsdistal end and is affixed into a mounting guide 310 located in the front315 of the movable nose 300. The tip 210 may be a drive for mountinginstruments, an instrument which is used for tightening fasteners, or acutting instrument. To effectively apply torque via the tip, the tipmust be engaged. In some instances, said engagement will be with afastener. In other instances, said engagement may be with material to becut or resected.

The circular nose 300, is formed with a diameter fits within said openproximal end 115. On the backside of the movable circular nose is afirst gear 350 with gear teeth 351 and a pin mounting catch 370. Thegear has a diameter which allows it to pass through the centered channel150. A bearing shoulder is formed around the gear 350 which rests onsaid circular wall 130.

A clutch 500 including a second gear 501 is inserted into the distal end120 fitting within the back section 145. The clutch has an annular outerwall 502, gear teeth 505 at top end which mate with the gear 350 on themovable nose 300. The clutch also has a drive-catch 515 formed in theannular wall 502 and a pass through channel 520 which in conjunctionwith the annular wall forms a cup shaped internal cavity 522. Thedrive-catch mates with a drive spline 160 on the handle 100.

FIG. 6 is a cut-away sectional view of FIG. 4 along the line of “A-A”the pin 610 fitted within the mounting catch 370 which is within thepass through channel 520 of the clutch 500. The drive catch 515 of theclutch is shown with the drive spline 160 extended from the interiorannular wall of the back section 145.

Via pass-through channel 520 the swappable torque limiting fixture(STLF) 600 which sets a predetermined torque for the device is inserted.Prior to insertion a coil spring 700 is placed on the STLF 600. The STLFis further comprised of a mounting pin 610 at a distal end, a body 620contiguous with the pin and a extended flange 630. The flange has abearing surface 640 on one side and a head surface 650 opposite thebearing surface. The coil spring 700 rests at a first end against thebearing surface 640 and at the other end against a channel bearing 550within the cup shaped internal cavity 522 fluidly connected to the passthrough channel 520. The pin 610 mates with a mounting guide 370 on anextended neck 375 formed on the backside of the movable circular nose300. Once inserted firmly, the pin is completely encased in the mountingguide. The spring 700 is compressed a fixed amount determined by thelength of the body 620. During assembly and/or to set a specific torquelimit, a STLF is selected with a body 620 and a coil spring 700 which incombination set a selected torque limit.

During assembly of a torque limiting driver a device utilizing primarilythe same components and with the same form factor may be set to apredetermined torque limit via selecting and assembling (or replacing) aparticular STLF. The primary components consisting of at least thehandle (molded body), movable nose and clutch, also referred to as aunitary based. In some instances, the end cap may be part of the unitarybase. In some instances, the coil spring may be part of the unitarybase. Springs may also be swapped to further alter or fine tune thetorque range. In some instance a selection of STLF and/or springs may bepacked together for onsite or on demand assembly to obtain the selectedtorque in the disposable device.

The pin 610 may be formed of a plastic or other material which is moremalleable (or deformable) than the mounting guide 370, thereby causingthe inserted pin 610 to deform to fit into the mounting guide. In someinstances, the mounting guide is softer than the pin and deforms toaccommodate the pin.

The swappable torque limiting fixture (STLF) 600 depicted in FIGS. 7Aand 7B may be varied in body 620 length. Changing the body length willalter the compression and/or limits placed on the coil spring (shown inFIGS. 1-6 and 8) at the boundaries (bearing surfaces) wherein swapping aSTLF with a longer body for one with a shorter body will decrease forcerequirements of a torque limiting driver utilizing the above exemplaryimplementations. The STLF has a pin 610 for mounting or catching theSTLF into an object with an additional bearing surface. The body 620 isof selectable length. The flange 630 extends radially around the bottomedge 622 of the body. On the back side of the flange is the rear surface650. An identifier 660 may be formed or placed on that back surface.Identifiers may include numbers, colors, letters, symbols or othervisual designators which may be used to indicate the properties of theSTLF and/or the torque limits it would impart to a device 10 it was usedin.

FIG. 8 shows a component view of the clutch 500 engaged with the nose300 via the STLF with the pin 610 affixed within the mounting guide 370and having coil spring 700 compressed between bearing surfaces. Thebearing surface 640 on the flange 630 and bearing surface 550 along theannular wall forming the pass through channel 520 form boundaries forthe coil spring. The selection of the body 620 length and/or thecompression properties of the coil spring will adjust the torque limitsof this device. Within functional limits, a longer body 620 (with afixed properties spring) will result in less force requirements. Ashorter body 620 will result in greater force requirements.”

FIGS. 9A-9E show five variations on latch and catch configurations ofmating the STLF pin into a mounting guide of the nose. These do notrepresent all potential configurations but those of ordinary skill inthe art will recognize that variations on these mounting configurationsare within the scope of this disclosure.

FIG. 9A indicates a tri-lobe mounting guide 380 in the extended neck 375guide which receives a generally round or ovoid pin 612 extended fromthe body 620. FIG. 9B indicates a ribbed tri-lobe mounting guide 382 inthe extended neck 375 guide which receives a generally tri-lobe pin 614extended from the body 620. FIG. 9C indicates a square mounting guide384 in the extended neck 375 guide which receives a generally square pin616 extended from the body 620. FIG. 9D indicates a rounded mountingguide 386 in the extended neck 375 guide which receives a generallygeometric (hexagon in this instance) pin 618 extended from the body 620.Rib 383 is deformable upon insertion of pin 614. FIG. 9E indicates agenerally geometric mounting guide 388 in the extended neck 375 guidewhich receives a generally geometric (hexagon in this instance) pin 618,pin 614 extended from the body 620. The pin and mounting guide cooperatein mounting via deformation fit, friction fit, adhesive fit, pressurefit and the like.

While the method and apparatus have been described in terms of what arepresently considered to be the most practical and preferredimplementations, it is to be understood that the disclosure need not belimited to the disclosed implementations. It is intended to covervarious modifications and similar arrangements included within thespirit and scope of the claims, the scope of which should be accordedthe broadest interpretation so as to encompass all such modificationsand similar structures. The present disclosure includes any and allimplementations of the following claims.

It should also be understood that a variety of changes may be madewithout departing from the essence of the disclosure. Such changes arealso implicitly included in the description. They still fall within thescope of this disclosure. It should be understood that this disclosureis intended to yield a patent covering numerous aspects of thedisclosure both independently and as an overall system and in bothmethod and apparatus modes.

Further, each of the various elements of the disclosure and claims mayalso be achieved in a variety of manners. This disclosure should beunderstood to encompass each such variation, be it a variation of animplementation of any apparatus implementation, a method or processimplementation, or even merely a variation of any element of these.

Particularly, it should be understood that as the disclosure relates toelements of the disclosure, the words for each element may be expressedby equivalent apparatus terms or method terms—even if only the functionor result is the same.

Such equivalent, broader, or even more generic terms should beconsidered to be encompassed in the description of each element oraction. Such terms can be substituted where desired to make explicit theimplicitly broad coverage to which this disclosure is entitled.

It should be understood that all actions may be expressed as a means fortaking that action or as an element which causes that action.

Similarly, each physical element disclosed should be understood toencompass a disclosure of the action which that physical elementfacilitates.

Any patents, publications, or other references mentioned in thisapplication for patent are hereby incorporated by reference. Inaddition, as to each term used it should be understood that unless itsutilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood asincorporated for each term and all definitions, alternative terms, andsynonyms such as contained in at least one of a standard technicaldictionary recognized by artisans and the Random House Webster'sUnabridged Dictionary, latest edition are hereby incorporated byreference.

Finally, all referenced listed in the Information Disclosure Statementor other information statement filed with the application are herebyappended and hereby incorporated by reference; however, as to each ofthe above, to the extent that such information or statementsincorporated by reference might be considered inconsistent with thepatenting of this/these disclosure(s), such statements are expressly notto be considered as made by the applicant(s).

In this regard it should be understood that for practical reasons and soas to avoid adding potentially hundreds of claims, the applicant haspresented claims with initial dependencies only.

Support should be understood to exist to the degree required under newmatter laws—including but not limited to United States Patent Law 35 USC132 or other such laws—to permit the addition of any of the variousdependencies or other elements presented under one independent claim orconcept as dependencies or elements under any other independent claim orconcept.

To the extent that insubstantial substitutes are made, to the extentthat the applicant did not in fact draft any claim so as to literallyencompass any particular implementation, and to the extent otherwiseapplicable, the applicant should not be understood to have in any wayintended to or actually relinquished such coverage as the applicantsimply may not have been able to anticipate all eventualities; oneskilled in the art, should not be reasonably expected to have drafted aclaim that would have literally encompassed such alternativeimplementations.

Further, the use of the transitional phrase “comprising” is used tomaintain the “open-end” claims herein, according to traditional claiminterpretation. Thus, unless the context requires otherwise, it shouldbe understood that the term “compromise” or variations such as“comprises” or “comprising”, are intended to imply the inclusion of astated element or step or group of elements or steps but not theexclusion of any other element or step or group of elements or steps.

Such terms should be interpreted in their most expansive forms so as toafford the applicant the broadest coverage legally permissible.

The invention claimed is:
 1. A torque limiting device comprising: ahollow body with and open proximal end and open distal end forming ahandle; an internal wall bisecting said hollow body into a first and asecond section; a channel formed through said internal wall fluidlyconnecting said first and said second sections; a nose supported on acircular base which fits movably into said hollow body; a front side ofsaid nose with a tool extending therefrom; a backside with said nosehaving gears, an extended neck and a pin mounting guide and a bearingsurface; a clutch having gears on its top, a pass through channeltherein, an annular wall surrounding the gear, a bearing surfacesurrounding the gear, and a drive catch formed in the annular wall; acoil spring fixed to the pin mounting guide via the pass throughchannel; a swappable torque limiting fixture (STLF) having an elongatedbody with a pin at one end and a flange with bearing at the other end;an identifier on the back side of the flange whereby a torque limit isdesignated; a drive spline extending from the internal wall of thehollow body and aligned with the drive catch.
 2. The device of claim 1,further comprising: a circular cap fitted into the distal end of thebody; and, a window through the back of the cap.
 3. The device of claim2, further comprising an identifier on the back side of the flange whichis visible through said window.
 4. A kit for forming a torque limitingdevice comprising: a partially assembled torque limiting devicecomprising; a hollow body with and open proximal end and open distal endforming a handle; an internal wall bisecting said hollow body into afirst and a second section; a channel formed through said internal wallfluidly connecting said first and said second sections; a nose supportedon a circular base which fits movably into said hollow body; a frontside of said nose with a tool extending therefrom; a backside with saidnose having gears, an extended neck and a pin mounting guide and abearing surface; a clutch having gears on its top, a pass throughchannel therein, an annular wall surrounding the gear, a bearing surfacesurrounding the gear, and a drive catch formed in the annular wall; acoil spring fixed to the pin mounting guide via the pass throughchannel; a selection of swappable torque limiting fixture (STLF) eachhaving an elongated body with a pin at one end, a flange with bearing atthe other end and an identifier on the STLF providing a visual quecorresponding to the torque properties of the device if it uses thatparticular STLF; a drive spline extending from the internal wall of thehollow body and aligned with the drive catch.